Braking arrangement for railway hopper cars



United States Patent Robert E. Campbell Arlington Heights, Illinois [72] Inventor Chicago, Illinois a corporation of Illinois [54] BRAKING ARRANGEMENT FOR RAILWAY 197. l98-2031GT1 [56] References Cited L'NITED STATES PATENTS 3.372.779 3/1968 Roselius et a1 188,197X 3,378,112 4/1968 Roselius et a1. 188/197 Primary Examiner-Duane A. Regcr Attorney Parker. Carter and Markey ABSTRACT: A braking arrangement for a railroad hopper car has a separate slack adjuster and brake cylinder on each end of the car. One end of one slack adjuster is pivoted to the ear frame and horizontally disposed on one side of the car center sill with the brake cylinder on the other side. The brake linkage extends from a vertical disposed cylinder lever on one side of the truck to the other side of the truck and to a vertical bell crank lever connected to the slack adjuster. A trigger connection extends between the cylinder lever and the slack adjuster. The trigger mechanism is arranged inward of the car end and below the slope sheet in an unexposed position.

Patentd Oct. 13, 1970 Sheet INVENTOR. ROBERT E. CAMPBELL PARKER CARTER & 'MARKEY ATTOR N EYS Patented Oct. 13, 1970 3,533,492

Sheet 3 of3 INVENTOR.

ROBERT E. CAMPBELL BY.

PARKER ,CARTER 8s MARKEY ATTORNEYS BRAKING ARRANGEMENT'FOR RAILWAY HOPPER CARS CROSS REFERENCE TO RELATED APPLICATION DESCRIPTION OF THE PRIOR ART In the well known hopper type railroad car, the brake controlling equipment including the brake cylinder, control valve, reservoir and various connecting parts, are all arranged and supported in the usual manner at only one end and below the sloped wall of the car. This necessitates the use of long connecting rods and linkage extending beneath the center sill of the car from one end to the opposite truck end for control of the brakes at that end. This often rendered it difficult and unsuitable to provide and install automatic slack adjusters. Furthermore, the aforesaid braking equipment, linkage, and tie rods, were exposed at all times to weather conditions. Fire employed for thawing out frozen contents of the hopper car would damage and render the equipment, such as slack adjusters, inoperative. Flying stones and dust tend to damage and clog the parts and it was difficult to install, service and maintain the equipment. The present trend is to increase the length of hopper cars, and this tends to aggravate the problems encountered.

SUMMARY OF THE INVENTION In accordance with the present invention entirely separate and individual sets of braking equipment are arranged on each end of the hopper car, which equipment is associated with and controls the brakes on only one end of the car, thereby eliminating the excessively long rods, and reducing the number of leversand brake rigging usually required along the full length of a car. A reduction of the possiblity of damage to the linkage and elimination of sagging and loose rods is thereby achieved. A substantial reduction in weight and less friction load on the brake rigging, affecting the braking force, also results thereby enabling a saving in the amount of braking power required to operate the brakes, so that smaller brake cylinders having a shorter stroke of the push rod, can be employed. The improved braking arrangement enables a slack adjuster to be used which is much smaller and shorter in length and therefore less expensive and lighter in weight. The

equipment is mounted and arranged compactly below the slope sheet and inward from the car end where it is less conspicuous and best protected from damage or tampering.

The invention contemplates a novel braking system in which the brake cylinder is mounted horizontally in the car frame and is connected to a vertical disposed cylinder lever pivoted to the car frame. The cylinder lever connects with the braking linkage to one set of brake shoes on one side of the car truck. The slack adjuster is horizontally disposed on the opposite side of the center sill of the car and pivoted at one end to the car frame. The other end of the slack adjuster is connected to a vertical bell crank lever and then to the braking linkage and to the other set of brake shoes on the other side of the car truck. A tie rod connects the truck levers between the two sets of car wheels. With this arrangement the brake cylinder is connected directly to one end of the braking system while the slack adjuster is connected at the extreme other end as an anchor. The brake linkage for the brake shoes is thereby tied into the system at an intermediate position between the two levers. The result is that the full braking force is evenly and directly applied to the wheels by the brake cylinder and none is expended on the slack adjuster which controls the slack conditions only after the braking force has been applied to the brakes.

The angularity of the push rod, the live and dead levers, and the associated truck levers for the brake shoes, is relatively constant, and any slight adverse angularity will be manifested.

on the anchor side of the opposite truck and at the slack adjuster where it is ineffective to interfere with the production of uniform breaking power upon the brake shoes. Since each set of braking equipment is associated with only one end of the hopper car, the movement of the levers, push rod and other linkage, is relatively small to produce the necessary braking power required.

The invention consists of the various features of construction, operation and combination of the parts and elements, as will be more fully pointed out hereafter, together with the drawings and in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of a hopper type of railway car showing the braking equipment of the invention on each end of the car;

FIG. 2 is a diagrammatic showing of the brake linkage at each end of the railway car;

FIG. 3 is a side view of a portion of a hopper car showing the braking arrangement at one end of the car;

FIG. 4 is a top view of FIG. 3; while FIG. 5 is a right end view of FIG. 3 withcertain parts of the car left off.

In describing the invention only those parts and elements essential to a clear understanding of the same, have been illustrated. Other parts actually present in hopper cars, to which the present invention particularly pertains, have either been shown in diagram form or been eliminated as unnecessary for a clear understanding of the same to those skilled in the art. Mention is made of the usual AB control valve, emergency and auxiliary reservoirs, brake pipe line, etc., all of which in the present instance are located at only one end (the B end) of the car and under the slope sheet; whereas duplicate sets of the braking arrangement of the invention, including the brake cylinder and slack adjuster, are located at each end of the hopper car and operate entirely independent of one another. For the sake of clarity some of the supporting brackets and struts on the car have also been left off or indicated only generally.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now specifically to the embodiment of the invention illustrated in the drawings, the railway car may be of any conventional type of freight car, for example, a hopper car 5 having the usual hoppers 6 and 7 and the center sill structure 8 extending between the two ends of the car and which is straddled by the hoppers. The sloped walls 9 and 10 on each end of the car are connected to the upright supports 12 and I3, supported in turn on their bottom ends upon the decks 14 and 15 on the under frame of the car and above center sill 8. The decks l4 and 15 are preferably arranged to more or less close off the bottom of the car at each end of the car and to serve as a support for the various elements of the brake control equipment and other parts to protect the same from flying stones, weather conditions and the heat from fires thawing out the contents of the car when necessary. Suitable supporting struts such as 16 between the slope sheet 9 and deck 14 and other struts 17 between the slope sheet 9 and support 12, are provided for reinforcing and supporting purposes. These and other struts not shown, may be suitably welded or riveted in place.

In the description which follows the equipment and its operation will be described with reference to only one end of the hopper car, for example, the end indicated at 8" in FIG. 1, and it will be understood that the opposite end indicated at A" is substantially a duplicate thereof and that there are no interconnecting rods, levers and such between the two ends of the car, except for an air brake pipe (not shown) connecting the two brake cylindersjThe usual AB" control valve, reservoirs and other necessary elements, are however mounted on only one end of the car,'the 8" end.

The brake cylinder 20 is mounted in a horizontal position below the slope sheet 9 and bolted upon a support bracket 19 welded between the strut 16 and the deck 14. The-push rod 2] of the, brake cylinder extends outward where its clevis is pivoted at 22 to an intermediate portion of the vertically disposed cylinder lever 23. The lower end of cylinder lever 23 extends downward and projects through an opening in the deck l4 and at its lower end has a pivoted connection 24 to which one end of the brake tie rod 25 is connected. The upper end of the cylinder lever 23 is pivotally supported at 27 from horizontal supporting strut 17 so that the cylinder lever hangs perpendicular to the brake cylinder 20 and is adapted to swing about pivot 27 when acutated by the push rod 21. The strut 17 is supported at one end from the end strut 12, and at the other end by the strut 16. Both the brake cylinder 20 and associated cylinder lever 23 are arranged adjacent one side of the center sill 8 and above one set of car wheels and truck as seen in FIG. 4. A hand brake connection on the cylinder lever 23 is indicated at 30 and extends in the usual manner to the hand wheel tnot shown) at the B end of the car.

A slack adjuster is provided in the braking arrangement and is preferably of the type in which slack is automatically taken up as wear takes place in the brake shoes and linkage, and is automatically let out whenever new brake shoes are installed. A slack adjuster which is suitable for the purpose is one of the construction and operation as shown in U.S. Pat. No. 3,326,335, issued June 20, 1967. In the present instance the slackadjuster indicated at 35, is pivotally supported at 36, at its left hand end, to the strut 37 below the strut 17, so that it is parallel to and horizontally disposed with respect to the brake cylinder 20 and the center sill 8. The slack adjuster at its right hand end and extending outwards towards the car end is pivotally connected at 38 to the upper end of a bell crank lever 40 which in turn is pivotally supported at an intermediate point 41 to a supporting bracket 42 fastenedto the car frame and center sill 8. The lower end 43 of the bell crank lever 40 extends below the deck 14 and center sill 8 for pivotal connection with the flexible linkage 45 in turn connected to the brake linkage. As more clearly seen in FIGS. 4 and 5, the slack adjuster 35 is located and arranged on the opposite side of the center sill 8 from the brake cylinder 20 and spaced therefrom between the wheels 46 and 47 and above the axle 48.

The braking linkage for applying the braking force of the brake cylinder 20 to the brake shoes includes the brake rod 25 pivotally connected at one end 24 to the bottom of cylinder lever 23. The other end of rod 25 is pivotally connected at 50 to one endof a dead lever 51 located outboard of the car truck from the brake cylinder 20 and slack adjuster 35. Dead lever 51 is pivoted intermediate its ends at 52 to a bracket 53 welded across the bottom of center sill 8. The other end of dead lever 51 pivotally connects at 54with tie rod 55 to the conventional brake truck actuating lever 57 located on one side of the car truck for operation of the brakes on the set of wheels on that side. On the other side of the car truck the link 45 connected to the bottom 43 of the bell crank lever 40 is wherein the brake cylinder 20 is connected to one extreme end of the brake linkage or rigging while the other end of the linkage is connected tothe slack adjuster 35 as clearly depicted in FIG. 2. This enables full braking power to be applied directly to both sets of brakes while adjustments for slack conditions are made after the full power brake application. This system accordingly does not deprive the braking effort of power ordinarily wasted or lost by connecting the slack adjuster in an intermediate position in the brake linkage, as is customarily done.

The slack adjuster 35 is provided with trigger means for controlling the actuation of the slack adjuster in correcting for abnormal slack conditions in the brake rigging. The trigger arrangement extends between and interconnects the brake cylinder lever 23 and the slack adjuster 35. It includes a fixed rod or shaft 71 extending across the space between the brake cylinder and the slack adjuster and anchored at each end in the upright strut 17 and 34 respectively. At opposite ends-of the rod 71 arms 72 and 73 are pivoted at their upper ends for swinging movement about the rod 71. A second rod 74 below rod 71 extends between the arms 72 and 73 connecting them together in fixed relationship so that both arms 72 and 73 can move and swing together about their pivotal connection on rod. 71. The lower end of arm 72 is pivotallyconnected at 75 to a trigger rod 76, the other end of which is pivotally connected at 77 to a point in the cylinder lever 23 located between the fulcrum end 27 of the cylinder lever 23, and the brake cylinder connection 22. The lower end of the other arm to engage the bracket 79 whenever the trigger mechanism is operated.

The foregoing trigger linkage arrangement is constituted so that any movement of the cylinder lever 23 by the brake cylinder 20 beyond a certain distance proportionally causes the trigger rod 74 to rotate the arms 72 and 73 to swing about the pivoted rod 71 and force the actuator rod 78 to engage the bracket 79. This results in the slack adjuster functioning in a manner to compensate for abnormal slack conditions as will be pointed out hereafter.

The drawings illustrate the running position of the railroad car with the brakes released, and in describing the operation of the various elements it is pointed out that the ratios and forces applied are carefully calculated so that the maximum possible braking effort is applied to the brakes with a minimum movement of the elements. Since the braking equip ment is associated with only one truck of the hopper car, it is not necessary for the push rod 21 to be extended so as to operate within the standard distance of about 8 inches as required by railroad regulations. Therefore in the present instance the push rod stroke can be shortened to at least 4 inches and the brake cylinder 20 consequently shortened and made smaller in capacity without impairing brake efficiency. Furthermore the length of the slack adjuster 35 can be considerably reduced due to its novel support and arrangement with the bell crank lever 40 since it is required to compensate for brake shoe and rigging slack conditions at only one truck.

DESCRIPTION OF OPERATION Assume the railroad car to be in the running position and with the brakes released as shown in FIG. 3. To produce a braking action air pressure is admitted into the brake cylinder 20 in the usual manner to project its push rod 21 forward. With normal wear assumed on the brake shoes and rigging, the push rod moves cylinder lever 23 outward about its pivot 27 so that the lower end pulls the tie rod 25 and begins to apply the brakes through the connected linkage as pointed out heretofore. Prior to the attainment of the full stroke of 4 inches of the push rod 21, the cylinder lever 23 begins to actuate the trigger rod 76 to swing the arms 72 and 73 about the rod 71 so that the actuating rod 78 carried by arm 72 engages the bracket 79 on the slack adjuster 35 to control the same in a manner to lock it up in a solid link in the brake linkage as described in detail in the patent aforesaid, to which reference is hereby made. The right hand end of the slack adjuster is consequently held locked against movement as well as the bell crank lever 40.

As the tension increases in the brake rigging due to further projection of the push rod, the brakes are firmly applied through the brake linkage from the cylinder lever 23, pull rod 25, dead lever 51, tie rod 55, actuating truck lever 57, to the brake beam 58 and finally to the brake shoes. The braking force is also extended through the tie rod 62 and across the truck to the truck lever 61, brake beam 59 and the brake shoes, link 45, and bell crank 40, which is now solidly anchored. The full force of the braking power from the brake cylinder is now directly expended upon the brake shoes and none is lost due to any intermediate slack adjuster connection as formerly, the slack adjuster in the present instance serving merely as an anchoring point in the brake linkage.

in the event that new brake shoes have been installed, the action of the brake control equipment is such that slack is automatically let out during brake application, When the brake shoes engage the car tension is increased inthe system causing the slack adjuster to lengthen and let out slack before the cylinder lever 23 can activate the trigger mechanism to affect the slack adjuster. The bell crank lever 40 is thereby pulled clockwise by the pull of the brake linkage. When the push rod 21 has been extended to almost its full amount the trigger mechanism is actuated so the actuating rod 78 engages the bracket 79 on the slack adjuster operating the same to lock up the slack adjuster as a solid link in the brake linkage.

Upon brake release, the power spring in the slack adjuster, as well as the weight of the braking equipment, restores the elements to normal running condition. The ratios and angularity between the slack adjuster, the bell crank lever 40, the cylinder lever 23, and the brake cylinder push rod 21, are such that only a small movement of the slack adjuster is necessary to correct any slack condition. The slack adjuster can therefore be made much smaller and easily fits into the horizontal position in the car end.

As the brake shoes become worn and looseness develops in the braking system, the push rod 21 will necessarily be projected beyond its normal limit of travel, thereby indicating an excess of slack. The slack adjuster is arranged to automatically take up the slack upon release of the brakes so that upon the next brake application the push rod stroke will benormaL With the presence of excess slack, the slack adjuster acts as a solid link when tension builds up in the braking system and the brake shoes engage the car wheels, overcoming the power spring in the slack adjuster. This lockup occurs when the cylinder lever 23 operates the trigger linkage so the collar on actuating rod engages the abutment on the slack adjuster. Upon subsequent brake release the power spring in the slack adjuster forces the slack adjuster inward shortening the same to take up the excess slack and restoring the trigger linkage and other parts to normal again. Upon the next brake application the brake system will be in normal condition and the push rod effective to operate within its normal stroke of 4 inches to properly apply the brakes.

Many important advantages accrue from the present invention. There is a great reduction in the number and length of the brake rods and levers, and only small movements of the operating elements are necessary to accomplish the braking action. There is also a more positive and reliable correction of abnormal slack conditions. In addition there is the desirable effect of relatively constant angularity of the push rod and the associated levers and brake rods on one car truck, so the most effective use is made of the full braking power upon the brakes. Also the failure of one set of brakes on one end of the car will not affect the braking equipment on the other end of the car, Another advantage gained is that the slack adjuster and brake cylinder can be made much smaller so that economies in costs can be realized, as well as a space and weight saving at the end of the car for better accommodations of the other necessary brake control equipment such as the usual AB control valve, reservoir, brake cylinder release valve, retainer valve, and other elements.

One of the principal features of the invention is locating the operating mechanism so that it is compactly arranged below the slope sheet of the railroad car and occupies as small a space as possible inward from the car end. The trigger mechanism, levers, and linkage are also arranged compactly behind the slack adjuster and brake cylinder and below the slope sheet remote from the end of the car. By arranging the elements as far away from the end of the car as possible, the danger of damaging the equipment as by fire is greatly reduced. Since it also is relatively inconspicuous, the tendency of tampering with the equipment is greatly minimized. The compact arrangement in addition is readily accessible for ser vicing, maintenance, and installation.

Whereas the invention has been disclosed, in connection with hopper type railroad cars. it may be applicable to cars of other types as is readily understood, without departing from the general concept of the invention.

l claim:

1. in a braking arrangement for hopper cars, a separate brake cylinder and an automatic double-acting slack adjuster located on each end of the car below the sloped wall of the hopper car, each brake cylinder and each slack adjuster being arranged in parallel horizontal relationship with respect to one another, one end of each slack adjuster being pivoted adjacent the sloped wall of the car and the other end being free and extending horizontally outward towards the car end, a vertical disposed cylinder lever pivoted at its upper end below the sloped wall and arranged perpendicular to said slack adjuster and brake cylinder, the lowerend of said cylinder lever extending below the base of the hopper car, said brake cylinder being operatively connected to an intermediate position on said cylinder lever, a bell crank lever pivoted to the hopper car frame and having its upper leg pivoted to the free end of said slack adjuster, the lower leg of said bell crank lever extending downward below the base of the hopper car, and intercon necting brake linkage means between the lower end of said cylinder lever and the lower end of said bell crank lever, said brake linkage being also connected to the brake shoes for actuation of the brakes by said brake cylinder.

2. In a braking arrangement for railroad cars, a brake cylinder and a slack adjuster arranged in parallel horizontal relationship above the center sill of the car, a vertically disposed cylinder lever pivotally supported at its upper end from the car frame and having its lower end extending below the center sill, said brake cylinder being pivotally connected to an intermediate portion of said cylinder lever, a bell crank lever pivotally supported at an intermediate portion on the car frame and having its lower end extending below the center sill, said slack adjuster being pivotally connected to the car frame at one end and having the other end pivotally connected to the upper end of said bell crank lever, and interconnecting brake linkage means extending between the lower end of said cylinder lever and the lower end of said bell crank lever, said brake linkage means also being connected to the brake shoes for actuation of the brakes by said brake cylinder.

3. In a braking arrangement for hopper type railroad cars having a slope sheet and a center sill, a separate slack adjuster and a brake cylinder arranged in horizontal parallel relationship below the slope sheet at each end of the hopper car and above the center sill, a separate vertically disposed cylinder lever pivotally supported at its upper end below each slope sheet at each end of the car, the lower end of each cylinder lever extending below the center sill, the brake cylinder at each car end'being pivotally connected to an intermediate point of the associated cylinder lever, a vertically disposed bell crank lever at each car end pivotally supported at an intermediate portion to the car frame and having its lower end extending below the center sill, each slack adjuster being pivotally supported at one end to the car frame and having its other end pivotally connected to the upper end of the associated bell crank lever, the slack adjuster at each car end being arranged on one side of the center sill and the associated brake cylinder on the other side of the sill, and interconnecting brake linkage means extending between the lower end of each cylinder lever and the lower end of each bell crank lever, said brake linkage means also being connected to the brake shoes for actuation of the brakes by the brake cylinder on the associated car end.

4. in a braking arrangement for a hopper type railroad car having a slope sheet and a center sill, a slack adjuster and a brake cylinder both arranged in horizontal parallel relationship at one end of the car and below the slope sheet, said slack adjuster and said brake cylinder also being arranged above and on opposite sides of said car center sill, a cylinder lever vertically arranged and pivotally supported at its upper end to the car frame below the slope sheet, the lower end of said cylinder lever extending downward below the center sill, said brake cylinder being pivoted to an intermediate point of said cylinder lever, a bell crank lever pivotally supported at an intermediate point to the car frame and having its lower end extending below said center sill, one end of said slack adjuster being pivotally supported to the car frame and having its other end pivotally connected to the upper end of said bell crank lever, said cylinder lever being located on one side of said center sill with the brake cylinder, and said bell crank lever being located on the' opposite side of said center sill with said slack adjuster, and brake actuating linkage means connected between the lower ends of said cylinder lever and said bell crank lever.

5. In a braking arrangement for a hopper type railroad car having a slope sheet and a center sill, a slack adjuster and a brake cylinder arranged in parallel horizontal relationship below said slope sheet and on opposite sides of said center sill, a cylinder lever vertically pivoted to the car frame at its upper end and having its lower end extending below said center sill, said cylinder lever being located at the same side of said center sill as said brake cylinder, said brake cylinder having its push rod pivotally connected to an intermediate point of said cylinder lever, a bell crank lever pivoted to the car frame on the same side of said center sill as said slack adjuster and above the center sill, said bell crank lever having its lower end extending below said center sill, said slack adjuster being pivotally supported at one end to the car frame and the other end pivotally connected to the upper end of said bell crank lever, a dead lever pivotally connected to said center sill and having one end connected to the lower end of said cylinder lever, and brake actuating linkage having one end connected to the other end of said dead lever and the other end of said brake linkage to the bottom end of said bell crank lever.

6. In a braking arrangement for hopper type railroad cars having a slope sheet and a center sill, a slack adjuster and a brake cylinder arranged in horizontal parallel relationship below the slope sheet of the hopper car and above the center sill, said slack adjuster being arranged on one side of'the center sill and the brake cylinder on the other side of the center sill, a vertically disposed cylinder lever pivotally supported at its upper end below the slope sheet, the lower end of said cylinder lever extending below the center sill on one side thereof, said brake cylinder having its push rod pivotally connected to an intermediate point of said cylinder lever, a vertically disposed bell crank lever pivotally supported at an intermediate portion on the car frame and having its lower end extending below the center sill on the other side from said cylinder lever, said slack adjuster being pivotally supported at one end to the car frame and having its other end pivotally connected to the upper end of said bell crank lever, interconnecting brake linkage means extending between the lower end of said cylinder lever and the lower end of said bell crank lever, and trigger linkage means operatively connecting said cylinder lever with said slack adjuster for controlling the actuation of said slack adjuster, said trigger linkage means being located inward from the end of the car and extending between said slack adjuster and brake cylinder under the slope sheet and across said center sill.

7. In a braking arrangement for railroad cars, a brake cylinder and a slack adjuster arranged in parallel horizontal relationship above the center sill of the car, a vertically disposed cylinder lever pivotally supported at its upper end from the car frame and having its lower end extending below the center sill, said brake cylinder being pivotally connected to an intermediate portion of said cylinder lever, a bell crank lever pivotally supported at an intermediate portion to the car frame and having its lower end extending below the center sill, said slack adjuster being pivotally connected to the car frame at one end and having the other end pivotally connected to the upper end of said bell crank lever, and interconnecting brake linkage means extending between the lower end of said cylinder lever and the lower end of said bell crank lever, said brake linkage means also being connected to the brake shoes for actuation of the brakes by said brake cylinder, and trigger linkage means connected between said cylinder lever and said slack adjuster for controlling the actuation of said slack adjuster, said trigger means being located inward from the car end below the slope sheet and between said slack adjuster and brake cylinder, said trigger means being pivotally supported from the car frame above the pivoted and supporting end of said slack adjuster and the supporting end of said brake cylinder.

8. The braking arrangement as claimed in claim 7, in which the trigger linkage means includes an actuator rod extending across the center sill between the slack adjuster and the brake cylinder and pivoted at each end to the car frame below the slope sheet, said actuator rod having one lever arm pivotally connected to said slack adjuster for control of the same and a second lever arm connected to said actuator rod and pivotally connected to said cylinder lever, said lever arms being rigidly connected to said actuator rod and located adjacent said slack adjuster and brake cylinder respectively.

9. The braking arrangement as claimed in claim 7, in which the trigger linkage means includes an actuator rod extending across the center sill and pivotally supported at each end to the car frame, said trigger linkage means being located inward from the end of the car and adjacent the supporting end of said slack adjuster and said brake cylinder, one linkage element of said trigger linkage means being operatively connected to said cylinder lever and another linkage element being connected to said slack adjuster. 

